Take note Theorem 6-5
Theorem
If a quadrilateral is a parallelogram, then its opposite angles are congruent.
If …
ABCD is a
Then …
A proof of Theorem 6-5 in Problem 2 uses the consecutive angles of a parallelogram and the fact that supplements of the same angle are congruent.
Problem 2 Using Properties of Parallelograms in a Proof
Proof
Given:
Prove:
Think
Why is a flow proof useful here?
A flow proof allows you to see how the pairing of two statements leads to a conclusion.
✓ Got It?
-
Use the diagram below.
Given:
Prove:
Table of Contents
- 6-1 The Polygon Angle-Sum Theorems
- 6-2 Properties of Parallelograms
- 6-3 Proving That a Quadrilateral Is a Parallelogram
- 6-4 Properties of Rhombuses, Rectangles, and Squares
- 6-5 Conditions for Rhombuses, Rectangles, and Squares
- 6-6 Trapezoids and Kites
- 6-7 Polygons in the Coordinate Plane
- 6-8 and 6-9 Coordinate Geometry and Coordinate Proofs